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Fasting Lipid Test

SamJB

SamJB

Well-Known Member
Messages
1,857
Location
Chester
Type of diabetes
Type 1
Treatment type
Pump
Hi all,
I've had my first round of blood tests since going low-carb and my LDL has shot up. I was told that I didn't need to fast as "they don't like diabetics fasting"; I get the impression that the test I had would have been the same had I fasted. So had my normal breakfast of omelette (made with butter and cheese) and had my bloods taken 30 mins later.

My LDL shot up from in the 3s when I was carbing, to the 5s. I thought that eating low-carb/high-fat wouldn't affect my LDL level. Now the doctor is talking about me going on statins (I'm only 28) and my girlfriend is on my back about going back on carbs.

So, should I now always fast before a lipid test?
 
Hi Sam on my last tests mine did that too. They went from 3.8 to 5.5. On that day before the test the last thing I ate was around 8pm and I had the blood taken at 8.30am the next day. Like yourself I was less than impressed so I asked for a retest which I had a couple of weeks later. For the next test the last thing I ate was at 6.00pm and I had the blood taken at 11.00am so I had fasted for a few hours more. The result was they came back as 3.9. In the 3 months between the tests I had not changed my diet at all so I was pretty convinced the 5.5 one must be wrong. The only difference between the tests was the length of fasting. If you don't think the results reflect what you've consumed then ask for the test to be done again.
 
I always fast before my blood tests - they are all done together at my 3-monthly check (lucky aren't I?) and it's easiest to fast. Usually for 12 hours minimum.

I did read somewhere that what you eat the day previous to a cholesterol test can affect the results, so after my usual breakfast of a 2-egg omelette cooked in butter I try to steer clear of too much fat for the rest of the day previous to the test. Sorry I don't have a source for that.

Also when you're in the early stages of a low-carb diet it's not unusual for your blood lipids to rise, but I think that's usually triglycerides which are released as you get into ketosis and start to metabolize your stored fat. (No source for that either! :oops: ). It settles down quite soon, though.

My best-ever lipid profile was after 18 months on Atkins Induction for weight loss, some years before I became diabetic. My most recent lipid profile, since being diagnosed Type 2 in April 2010, is almost as good and is within the guideline limits for all aspects.

Did they tell you your Total:HDL ratio? That is one of the most important figures; it should be below 5 and preferably close to 3.5.

Because of your age I assume you're Type 1? (haven't worked out yet how to look at a profile while typing a post :oops: ). That is most likely why they "don't like diabetics to fast". Work out how long you normally fast overnight (last meal through to breakfast) and try not to go longer than that. I usually eat nothing after 9pm at the latest, and don't breakfast until about 10am, but I'm Type 2 and don't have problems with fasting more than 12 hours.

I alway book my blood tests about 6 weeks in advance so I can be sure of getting the first appointment. Then I can replenish my caffeine levels asap! :wink: :lol:

Viv 8)
 
According to this website you do need to fast

http://www.livestrong.com/article/26154 ... erol-test/

since
Triglyceride levels increase after eating, affecting the LDL results. You need at least 12 hours after eating for the fat levels to return to equilibrium values before you give blood for a cholesterol fractions test. Alcohol also affects triglycerides levels. Measurements of the cholesterol fractions HDL and LDL provide a more complete picture of health than total cholesterol alone. Fasting is important to obtain accurate results.
Click to expand...

This doesn't mean that the study Phoenix linked to isn't correct, but it's possibly saying they're using the results of the test in a different way i.e. possibly ignoring or discounting the LDL result. Notice how this study uses/ disregards lipid markers depending upon whether the test is fasting/non-fasting

This study demonstrates that HDL cholesterol, triglycerides, total/HDL cholesterol ratio, and apolipoprotein A-1 predict CVD when measured nonfasting. By contrast, total, LDL, and non-HDL cholesterol, in addition to apolipoprotein B-100 and B-100/A-1 ratio, provide less useful CVD risk information when nonfasting
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http://www.ncbi.nlm.nih.gov/pubmed/18711012/

** LDL ... less useful CVD risk information when non-fasting **

Perhaps lipid profile testing will change but HCPs will interpret new non-fasting figures in a way that is only applicable to old fasting methods.
Obviously an area to watch

Geoff
 
This doesn't mean that the study Phoenix linked to isn't correct, but it's possibly saying they're using the results of the test in a different way i.e. possibly ignoring or discounting the LDL resultI
Click to expand...
Looked up a bit further
It seems that a non fasting test cannot test triglycerides but they suggest that it doesn't make any difference when calculating risk factors.
(still haven't got to the original paper but I think that this is the relevant info.)
http://www.cap.org/apps/cap.portal?_nfp ... bel=cntvwr

LDL cholesterol calculated from fasting samples used to measure triglycerides, total cholesterol, and HDL cholesterol is no more effective than using the non-HDL cholesterol level to predict the risk of vascular disease (Di Angel­antonio E, et al. JAMA. 2009;302:1993–2000). That’s good news because testing for non-HDL cholesterol doesn’t require a fasting sample. All that’s needed is simple arithmetic: Subtract HDL cholesterol from total cholesterol without regard to triglyceride. (Non-HDL-C is a measure that includes low-, intermediate-, and very-low-density lipoprotein cholesterol.The meta-analysis, which encompassed more than 300,000 patients and 10,000 major adverse events, also showed that triglycerides do not provide any independent information about coronary heart disease risk
Click to expand...
 
SamJB said:
My LDL shot up from in the 3s when I was carbing, to the 5s.
Click to expand...


That is some increase :shock:
 
Yes it is, noblehead!

Thanks for the advice guys. Some interesting comments here. I guess I'll fast next time and see if that makes a difference.
 
Hi Sam!

At my last cholestorol test, I forgot to fast :oops: They asked if I'd fasted and when I said that I'd forgotten to, they said they couldn't do it that day and I should make a new appointment and remember to fast.

I always stop eating at 6.00pm the night before and make sure I have an 8.30am appointment. I take my basal as normal in the morning, but no bolus. If I'm at the hospital for bloods, I take a little bowl of my normal breakfast with me and as soon as I've had the blood tests, I buy a cup of tea, jab my Apidra and eat my breakfast. If you tell the hospital or doctor's surgery you're Type 1, they'll make sure you get an early appointment and if it's a general drop-in blood-testing clinic, they'll queue-jump you.

As for the cholestorol levels, mine went up overall when i started low-carbing, but I can't remember the LDL going up. My HDL went up and Trigs went down, but I just can't recall what the LDL did. I'd try not to worry about it this once, but get it re-checked in 3 months and consider your diet in the light of that.

Smidge
 
smidge said:
I always stop eating at 6.00pm the night before and make sure I have an 8.30am appointment.
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That's a long fast Smidge, I was told 10-12 hours is sufficient and I normally just fast for 10 hours.... opting to eat my evening meal a bit later the evening before.
 
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